000
FXUS66 KHNX 131250
AFDHNX
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
550 AM PDT Tue Mar 13 2018
.SYNOPSIS...
A series of potent storms will impact the central California
interior through the week and the upcoming weekend. Periods of
moderate to heavy precipitation can be expected, with significant
snowfall accumulations in the mountains. The weather systems will
also produce breezy and cooler conditions across the region, with
temperatures dropping below seasonal normals.
&&
.DISCUSSION...
The initial round of precipitation impacted central California
during the evening and overnight last night with generally light
amounts so far. As much as a few hundredths in the SJ Valley and
up to a couple of tenths of an inch in the surrounding foothills
and higher Sierra. Snow levels are running 8000 ft and above in
the warm southwesterly moisturefetch. Temperatures across the
area are running several degrees above 24 hrs ago beneath the
warm cloud cover and will top out near or a bit above climo this
afternoon despite continued cloudy conditions, as moderate
southerly breezes prevail.
Current radar activity and high rez short term models indicate
additional showers developing and moving across our area through
the morning hours, with heavier precipitation developing in the
Sierra zones by early afternoon as favorable orographic conditions
set up. Snow levels will remain high during this period, near 8k
ft or more, and significant amounts of snow will accumulate in
the high Sierra. A Winter Storm Warning remains in effect for the
Sierra north of Kings Canyon, and a Winter Weather Advisory to the
south, where accumulations will be lower. Rainfall in the lower
elevations of the Sierra and foothills will need to be watched for
local flooding concerns, especially near recent burn scars.
Snow levels lower to 4500 to 5000 ft by Wednesday as the upper
trough responsible for the precip pushes into the west coast and
cooler air moves into our area. During this time, models bring
another impulse with additional precip into our area,
accumulating more snow in the Sierra, and impacting at least the
higher elevations in the Kern County mountains by Wednesday
evening.
Additional shortwave impulses are progged to move through the
Pacific trough through the week, bringing more periods of rain
and snow. Models are starting to come into better agreement on
timing and precip amounts with these impulses. Consensus is
starting to favor a slight break Thursday followed by another
round of moderate to heavy precip by Friday/Saturday. This will be
evaluated for the need for more winter highlights.
These incoming disturbances will also bring gusty winds over the
ridges and through and below mountain passes. So far they are not
expected to reach advisory levels.
.AVIATION...
Areas of mountain obcurations across the Sierra Nevada. In the
Tehachapi mountains areas of mountain obcurations after 23z Tuesday.
In the San Joaquin Valley areas of MVFR conditions due to rain
showers and mist. In the Kern County desert areas of MVFR conditions
due to rain showers and mist after 03z Tue. Otherwise, VFR
conditions are expected to prevail for the next 24 hours.
&&
.AIR QUALITY ISSUES...
None.
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
Winter Weather Advisory from 2 PM this afternoon to 11 PM PDT
Wednesday ABOVE 6500 FEET FOR THE CAZ097.
Winter Storm Warning from 1 PM this afternoon to 11 PM PDT
Wednesday ABOVE 6000 FEET FOR THE CAZ096.
&&
$$
public...JEB
avn/fw...MV
synopsis...JEB
weather.gov/hanford